1. Field of the Invention
The invention relates to a projection system, and more particularly, to a projection system including a movable projection apparatus used in vehicles.
2. Description of Related Art
Generally speaking, current display systems in vehicles allow drivers and passengers to watch at the same time. However, in recent years, authorities in the government have started to request drivers to watch vehicle information (such as a navigation image) only and forbid watching any entertainment images when the driver is driving the vehicle. Therefore, some manufacturers provide a set of on-board display system which provides two kinds of images at the same time; one image (such as a navigation image) is transmitted towards the drivers' direction, while the other image (such as an entertainment image) is transmitted towards the passengers' direction. In this way, the drivers and the passengers may watch the required images at the same time, and the drivers may not violate regulations of the government authorities. However, this set of on-board display system restricts what image the drivers watch and may not adjust itself according to the needs of the users correspondingly.
U.S. Pat. No. 7,580,186 discloses a multiple-view directional display for vehicles, the multiple-view directional display including a display, a lenticular screen, and a lens structure. US Patent Publication No. 20070177113 discloses a digital image projection system including a light source for providing illumination light, a reflective mirror, a condenser lens, a light valve, and a projection lens set. U.S. Pat. No. 7,443,582 discloses a screen and a projector, wherein a relative position of the screen and the projector may be adjusted.